Combing the race to decide Northern Ireland's three MEPs with councils elections for the first time could increase voter turnout, it has been predicted.

But as the contest formally got under way yesterday, there was also a warning that the Euro poll "always comes back to Northern Ireland politics" rather than EU issues.

Ulster Unionist standard-bearer Jim Nicholson argued the double Euro and council polls were the first elections in Northern Irelanad in almost three years and "people want to have their say".

The veteran, accompanied by party leader Mike Nesbitt, was first to sign the formal nomination papers at the Electoral Office in Belfast, followed later by TUV leader Jim Allister.

Mr Nicholson also signalled his intention to remain a member of the European Conservatives group in the Brussels Parliament if he is re-elected.

He rejected Conservative candidate Mark Brotherston putting a question mark over his membership of the Conservatives group after he was elected on a joint UUP/Tory ticket at the last Euro contest in 2009.

Mr Nicholson added: "I think it's fair to say this is the first European election doubled up with the local council elections and it is now some considerable time – almost three years – since there has been an election.

"So I think that people are keen to have an election and I think there will be a good turnout.

"It always comes back to Northern Ireland politics – a recent hustings event ended up debating events at Stormont – and that would be very unfortunate."

Former DUP MEP Mr Allister, meanwhile, argued sending him back to Brussels was "the swiftest and best route to change" – at Stormont. "Give TUV a province-wide mandate and change in Stormont is inevitable, as those scalded by the result are forced to make changes," he said.

Mr Brotherston argued Peter Robinson's suggestion that DUP voters should transfer to the UUP or Ukip demonstrated the three parties "are now all effectively the same".

"NI Conservatives are the only party which has a plan to move politics on beyond 'orange, green or something in between'," he said.